Emergency flotation devices are required on many aircraft to provide emergency assistance to passengers in the event the aircraft is forced down or must land in water. Emergency flotation devices generally include systems designed to float the aircraft, systems for deploying emergency life rafts and life vests for individual occupants. Oftentimes, the electrical systems on an aircraft, such as control systems and emergency systems, become inoperable due to a failure of the aircraft's main power system after exposure to water. Emergency flotation systems often require electrical power to deploy and a failure of the power system renders the flotation system inoperable if no backup power supply is available. As a result, various systems have been devised for providing emergency power to aircraft.
One commonly used method of providing backup power is to provide batteries that may be charged prior to or during flight. The batteries generally designed to allow a pilot sufficient power to maintain control over the aircraft until it can be safely landed after a failure of the main power system. Unfortunately, those battery systems are generally electrically connected with the main power system bus, which is generally too complex to isolate from the environment. In addition, the batteries themselves are not protected from exposure to the environment. As a result, the battery systems are susceptible to failure after being exposed to water.
Another example of a power system for an aircraft that is capable of providing emergency power is described in U.S. Pat. No. 5,606,247 to Sutrina as long as the engine is turning. The power system includes a mechanical gear drive that is driven by the aircraft's engine and a plurality of U-shaped cores each of which have two legs separated by a gap. A coil is wound on a portion of each core and an electronic converter selectively couples and decouples the coil from a dc power source. The relative motion between the gear teeth and the cores generates power. A disadvantage of the system is that the mechanical gears must rotate in order to generate power, which requires operation of the engine, and the engine is susceptible to failure from exposure to water. As a result, if the aircraft were to land in water and the engine ceased to operate no power could be supplied by the system.
In view of the above, there exists a need for an emergency power supply for an emergency flotation system that is not susceptible to failure from exposure to water.